TPS22963C: Clarifications on TPS22963C and TPS7A8300RGWT LDO's ON and EN pin's voltage ranges

Sreelakshmi T V

Part Number: TPS22963C

Hi,

I was using the Ic's TPS22963C(to generate VCCAUX_1V8 from 1V8)and TPS7A8300RGWT (to generate VMGTAVCC_1V and VMGTAVTT_1.2V from 1V8).The
EN pin (of TPS7A8300RGWT) and the ON pins (of TPS22963C) were driving from the PIC(3.3V) and the pins were used as the power sequencing
pins to power ON the Ic's(as per the enable sequence).

Now we are planning to power ON the supplies without programming the PIC.We are going to provide pull ups to EN and ON pins.We referred the
datasheets to check whether we can provide 1.8V to EN pin and ON pins(since the PIC pin is driving 3.3V ) with pull ups or not? (There are no translators in between the devices)

Thanks in advance
Sreelakshmi

over 6 years ago

0 Aleksandras_Kaknevicius over 6 years ago

TI__Genius 15710 points

Hi Sreelakshmi,

I can speak for the TPS22963C device, and in this case a 1.8V signal will be able to enable to the device. However, the enable has no pulldown integrated, so to keep the device off, the enable pin would have to be pulled down.

Thanks,

Alek Kaknevicius

0 Aleksandras_Kaknevicius over 6 years ago in reply to Aleksandras_Kaknevicius

TI__Genius 15710 points

Based on the datasheet for the TPS7A8300RGWT, the VIH level is 1.1V, so a 1.8V signal should work to enable the device without issue.

Thanks,

Alek Kaknevicius

0 Sreelakshmi T V over 6 years ago in reply to Aleksandras_Kaknevicius

Prodigy 40 points

Thanks for the reply.

1)Can we directly drive the 3.3V signal line from the PIC to the EN pin(without any voltage translator in between) of TPS7A8300RGWT,which is having 1.8V input supply??

2)Can we directly drive the 3.3V signal line from the PIC to the ON pin(without any voltage translator in between) of TPS22963C,which is having 1.8V input supply??

Thanks

Sreelakshmi

0 Aleksandras_Kaknevicius over 6 years ago in reply to Sreelakshmi T V

TI__Genius 15710 points

Hi Sreelakshmi,

Is the concern that the enable pin voltage is higher than the input voltage? For the TPS22963C, there is no issue in having VIN=1.8V and ON=3.3V. While I do not directly support the TPS7A8300RGWT device, there is nothing in the datasheet that leads me to believe that this would be a problem.

Thanks,

Alek Kaknevicius

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TPS22963C: Clarifications on TPS22963C and TPS7A8300RGWT LDO's ON and EN pin's voltage ranges